This invention relates to coil mountings in general and specifically to mounting of signal pickup coils.
In regulated power supplies especially those of the switch-mode type, it is well known to pass a current carrying conductor through a pickup coil which senses current changes therein and communicates the changes to regulating means for adjusting the power supply output accordingly. The "pancake" shaped pickup coils are quite often small and fragile and are generally housed in a mounting device having support posts for connection to a printed circuit board or the like. The pickup coil may be conventional and wound on a bobbin type form or may be toroidal and wound about a donut shaped ferrite core for higher frequency applications.
Present manufacturing techniques involve positioning a pickup coil on a support, placing the current carrying conductor in position through the central opening of the support and pickup coil, maintaining the respective conductor and coil positions while an epoxy cement locks the conductor to the coil, mounting the assembly to a printed circuit board and terminating the conductor. The pickup coil and conductor are thus maintained in a fixed relative position which satisfies various certification agencies such as Underwriters Laboratories and the Canadian Standards Association. In many power supply installations the signal pickup coil must be carefully positioned because contact with the conductor could compromise system power line isolation.
The above assembly technique, while generally effective, is time consuming and requires some operator skill. It also leads to waste if the proper length of conductor is not provided on each side of the coil, necessitating a new assembly. Consequently, there is a need in the art for a pickup coil assembly that would solve these problems and provide means for simply holding the conductor in fixed relationship to the coil and for permitting subsequent axial adjustment of the conductor, if needed.